Answer for I have planted several food plots about a month ago in the wildgame forage fury. They were doing fine but now some of the plants are starting to turn yellow and a light purplish color. Do I need to put nitrogen on them?

It depends on the plants we are talking about. Many brassicas will begin to turn purple in color as we get later into the fall. That being said, purple coloration is also indicative of a phosphorus deficiency which is required by plants for optimum growth. Yellowing can be related to nitrogen deficiency, but also can be cause by too little or too much water. If we are talking about nitrogen fixing plants like clover or beans, then it is likely a water issue and not nitrogen. But with Wildgame Forage Fury I would say that it is a nitrogen issue being most are brassica family species.
DeerGro assists in the freeing up and flow of nutrients like phosphorus and nitrogen to the plant, increasing the health and growth potential.